Even 200 mm of rainfall (200 liters per square meter) may fall in some regions of Poland between Thursday and Sunday. The Genoese low is approaching Poland, the same type of low that caused floods in the past, e.g. in 1997, 2010 and 2014. This time the situation is not as serious, but still dangerous – says Grzegorz Walijewski, deputy director of the Center for Hydrological Protection of the Country in an interview with Next.Gazeta.pl IMWM-PIB – At that time, rainfall totals were even greater than those forecasted for the coming days. In '97, rainfall exceeded 500 mm, in 2010 around 400 mm, in 2014 around 200 mm in 24 hours. Here, rainfall will not be as large, but these are still huge values - explains Walijewski.
When such a large amount of rain falls on dry soil, we observe increased surface runoff. Despite the low water levels in the riverbeds, the floods will be violent. This is a worrying situation. We may not be facing a nationwide catastrophe, but local floods in a small area may occur
– adds Walijewski.
And he explains that the parched soil will not absorb water, at least in the first part of the rainfall. This, in turn, will cause the surface flow to be increased. – We can already see it now, after the first rainfall after a long period of drought and heat, which we recorded on Monday and Tuesday. The runoff was very visible, the rivers reacted. At IMGW-PIB, we are on duty 24 hours a day, we are closely analyzing the latest forecasts of meteorologists and model results – says the hydrologist. However, he reassures that during the previous floods, the rainfall was more than twice as large.
Mean and dynamic than Genoese. Much can still change
What will happen on Thursday and the following days also depends on which way the Genoese low will turn. – Genoese lows are terribly “mean” to forecast. It is enough that it moves 100-150 km south of our border and these precipitations will not be so terrible. But today's predictions show that it will move north, towards Poland – explains Grzegorz Walijewski.
In his opinion, the current forecasts do not look optimistic and we should definitely prepare for meteorological warnings of the second, and maybe even the third degree. According to Tuesday's predictions, on Thursday and Friday the low will bring heavy rainfall in the southwestern part of the country, covering Lower Silesia, the Opole and Lesser Poland provinces, part of the Lubuskie and Greater Poland provinces, in the southern part.
On Saturday, however, precipitation will move more to the east and north, meaning it will cover the provinces of Lesser Poland, Subcarpathia, Świętokrzyskie, Łódź and most of Greater Poland, the entire Lubuskie and part of the center of the country.
According to today's forecasts, the low will return to Lower Silesia on Sunday, although it is difficult to say for sure, because this unpredictable pressure system may also stop. On Monday, dangerous precipitation may still occur, but it will be smaller and will again occur more in the south and west of the country.
– It doesn't look good. I really don't like this kind of low that sucks moisture from the Mediterranean Sea and often in the next phase from the Black Sea. Fortunately, they appear from time to time, but they don't always shape the weather in Poland. The question is, where will this low hit? Southern Poland, the Czech Republic and Slovakia, or will it move south and flood Austria, the Czech Republic and Slovakia, and only “slightly” Poland? – wonders Walijewski.
Here we have a certain amount of uncertainty. But today all models show that the dangerous low wants to approach Poland and discharge its energy in the form of heavy rain right in our country
– he adds.
“The situation in the models is currently clarifying and for the reasons mentioned above, the forecasts may change dynamically, even during the incident itself. Forecasts have been predicting a dangerous situation for several days, which cannot be underestimated,” experts from the Storm Observers Network note on X.
Climate change is pushing us from one extreme to another
We have just written about the record low water level of the Vistula in the Warsaw section, and now we are warning about local floods. Grzegorz Walijewski notes that this is what the world looks like in the era of climate change.
IMWM-PIB has a little over 600 hydrological stations in its measurement and observation network, which automatically measure water levels in rivers and their flows. On Sunday, 308 of them indicated a hydrological drought, reaching the levels of 2015, the worst drought in the last three decades. However, two days of rainfall were enough and this number dropped to 240 (which is still an alarming level), and much more intense rains are ahead of us.
The floods are only temporary, the water will drain away soon and we will “return” to drought. If it was just one episode, we would have a record drought and again over 300 stations would indicate low water literally within three to five days
– says Grzegorz Walijewski.
On the one hand, we have drought, and on the other hand, local flood threat. This is already becoming a characteristic feature of Poland's climate.
– summarizes the deputy director of the National Hydrological Protection Center at IMWM-PIB.